If a child misbehaves after multiple warnings, there are all kinds of things to be done before it comes to last resorts.
Most of these kinds of problems are caused by underlying anxieties or fears that a kid can't articulate. They WANT to succeed by the criteria that their parents set, but they can't for some reason. Repeated warnings only remind them of their failures, and make them suspect that the people setting the rules don't care whether those rules can be followed. So, they start to lash out. Wouldn't you? Spanking them in that situation just takes things to the next level of bad. If the kid ever does fall into line, it's not because the problem has been solved; it's because the child's will has been broken.
Most of these kinds of problems are caused by underlying anxieties or fears that a kid can't articulate. They WANT to succeed by the criteria that their parents set, but they can't for some reason. Repeated warnings only remind them of their failures, and make them suspect that the people setting the rules don't care whether those rules can be followed. So, they start to lash out. Wouldn't you? Spanking them in that situation just takes things to the next level of bad. If the kid ever does fall into line, it's not because the problem has been solved; it's because the child's will has been broken.